QTOF 6545 not seeing reference mass

Hi Simon,

When you turn on the reference mass in the software, do you see it spraying from the ref sprayer in the source?

We did find a blockage in the line between the bottle and nebuliser, which we flushed with a syringe. Doing the flush has allowed us to see the reference mass again, though the abundance is 3 orders of magnitude less than expected. We are using a fresh solution from a stock preparation made in September.

The instrument was off for a period due to an unrelated failure in the lab's UPS. 

I can not see any spray currently and we are thinking that the nebuliser, may also have a partial blockage.

Tubing should be replaced, part number G1969-60115 on Agilent.com.

We currently have a similar issue with our reference nebuliser on a 6546A QTOF. The reference mass solution comes through the restriction tubing fine but there is no spray and intensity of the reference ions are ~x100 lower than observed previously. I've tried a few nebulisers and no difference seen. What I did notice, however, is that the gas flow to the reference nebuliser is incredibly low, very gentle flow felt on my face.

So, I then went into tune menu of our 6546A QTOF and tried a few things..... 

1. I connected the N2 gas tubing, that usually goes into the Jetstream nebuliser, into the reference nebuliser and what a difference! The reference masses 121 and 922 very strong indeed, better than previously observed.
2. Whilst in tune, I dropped the nebuliser pressure to 2 psi and then raised the nebuliser pressure in 1psi intervals to a point where the responses for 121 and 922 ‘peaked’ at a nebuliser pressure of 7-8 psi. 
3. When I switch off calibrant A, the responses for 121 and 922 go close to zero which is what I expect.
4. In acquisition, however, when I switch calibrant A on and off the difference in response for 121 and 922 is insignificant and their intensities remain low. 

Is this a tubing problem or a gas flow issue?

Thanks.